Clean mushrooms with any dirt or debris and align the mushroom caps upside down in a baking pan.

In food processor, place all filling ingredients and process until evenly mixed.

In separate bowl, mix panko bread crumbs, butter, and fresh parsley.

Fill each mushroom generously with filling and then sprinkle panko mixture on top of the filling. (Each mushroom should have about 1 teaspoon of panko topping on it). Pat down so that the crust mixture sticks.

Then place in oven for about 15 minutes. If making these a day ahead, simply just cover and refrigerate until needed. The size of the mushroom may alter cooking time; be sure to check on the mushrooms after ten minutes to gauge the remaining time if any.